Many examples of housings for filtration of liquids are known. For example, in U.S. Pat. Nos. 2,313,612, 2,325,169, 2,392,354 and 2,435,115 to Alsop, various filter arrangements are disclosed. These filters interact with a central perforated post through which filtered liquid passes. These filter arrangements are acceptable where contamination of the fluid to be filtered is not critical.
Other examples of differing housings and filtration systems are disclosed in U.S. Pat. No. 956,914 to Ward, U.S. Pat. No. 2,655,397 to Augspurger et al., U.S. Pat. No. 3,193,129 to Pfluger et al., U.S. Pat. No. 4,267,940 to Wade, U.S. Pat. No. 4,588,503 to Sugiura, U.S. Pat. No. 4,853,120 to Frantz, and U.S. Pat. No. 5,178,753 to Trabold.
U.S. Pat. No. 956,914 discloses a method and apparatus for controlling and cleaning self-cleansing granular bed filters intended primarily for use in filtering water. Opposite ends of a filter casing are accessible by removal of bolts from a series of connected sections.
U.S. Pat. No. 2,655,397 discloses tank closure fasteners designed and adapted for use on top closures for rental-type water softeners.
U.S. Pat. No. 3,193,129 discloses a pressure container which consists of a plurality of individual sections, and which may be assembled from as many sections as are needed to form a cavity of desired volume by opening and closing a clamp fastener.
U.S. Pat. No. 4,267,940 discloses a connector which cannot be removed from parts or sections interconnected by the connector while such parts are displaced, as by pressure, relatively away from one another.
U.S. Pat. No. 4,588,503 discloses a liquid filter assembly for removing impurities contained in a liquid including a roll filter disposed within a casing.
U.S. Pat. No. 4,853,120 discloses a device for filtering fluids such as lubricating and fuel oils.
U.S. Pat. No. 5,178,753 discloses an oil filter for internal combustion engines.
An example of a sanitary filter housing for use with cartridge filters is available from Alsop Engineering Company as Model 12-SF. This sanitary filter housing includes a bottom plate to which is clamped a single, integral piece cover by a plurality of spaced-apart bolts. The bolts each pass through an L-shape fastener which grips a lip at the bottom of the cover as the bolts are tightened.